Meta-analyses reveal the large-scale spatial patterns of genetic and phylogenetic diversity for Chinese terrestrial vertebrates.

Background: Streptococcus mutans(S. mutans) is considered the most relevant bacteria during the transition of the non-pathogenic commensal oral microbial community to plaque biofilms that promote the development of dental caries. Oregano (Origanum vulgareL.), is a universally natural flavoring and its essential oil has been demonstrated to have good antibacterial effects. However, the specific antibacterial mechanism of oregano essential oil (OEO) againstS. mutansis still not completely understood.Methods: In this work, the composition of two different OEOs was determined by GC‒MS. Disk-diffusion method, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined to assess their antimicrobial effect onS. mutans. The inhibition of acid production, hydrophobicity, biofilm formation and real-time PCR forgtfB/C/D,spaP,gbpB,vicR,relAandbrpAmRNA expression byS. mutanswere assessed to preliminarily investigate the mechanisms of action. Molecular docking was performed to simulate the interactions with the virulence proteins and active constituents. MTT test using immortalized human keratinocytes cells was also performed to investigate cytotoxicity.Results: Compared with the positive drug Penicillin /streptomycin 100X (DIZ: 34.13 ± 0.85 mm, MIC: 0.78125 μL/mL, MBC: 6.25 μL/mL), the essential oils ofOriganum vulgareL.(DIZ: 80 mm, MIC: 0.625μL/mL, MBC:2.5μL/mL) andOriganum heracleoticumL.(DIZ: 39.67 ± 0.81 mm, MIC: 0.625μL/mL, MBC: 1.25μL/mL) could also exhibit similar effects to inhibit the acid production and reduce the hydrophobicity and biofilm formation ofS. mutansat 1/2-1MIC concentration. And gene expression ofgtfB/C/D,spaP,gbpB,vicRandrelAwere found to be downregulated. Due to the composition of essential oils from different sources being highly variable, through effective network pharmacology analysis, we found that OEOs contained many effective compounds, like carvacrol and its biosynthetic precursorsγ-terpinene andp-cymene, which may directly target several virulence proteins ofS. mutans.Besides, no toxic effect was instigated by OEOs at 0.1 μL/mL in the immortalized human keratinocytes cells.Conclusion: The integrated analysis in the present study suggested that OEO might be a potential antibacterial agent for the prevention of dental caries.

Sexually dimorphic (SD) traits are important in sexual selection and species survival, yet the molecular basis remains elusive, especially in amphibians where SD traits have evolved repeatedly. We focus on the Leishan moustache toad (Leptobrachium leishanense), in which males develop nuptial spines on their maxillary skin. Here we report a 3.5 Gb genome assembly with a contig N50 of 1.93 Mb. We find a specific expansion of the intermediate filament gene family including numerous keratin genes. Within these genes, a cluster of duplicated hair keratin genes exhibits male-biased and maxillary skin-specific expression, suggesting a role in developing nuptial spines. We identify a module of coexpressed genes significantly associated with spine formation. In addition, we find several hormones likely to be involved in regulating spine development. This study not only presents a high-quality anuran genome but also provides a reference for studying skin-derived SD traits in amphibians.

Gray mold caused by Botrytis cinerea is one of the most destructive postharvest decay of strawberry fruit. The present study aims to identify essential oils with antifungal activity against B. cinerea and the underlying mechanisms and their potential application in controlling postharvest decay. In the screening test, essential oils from Cymbopogon citratus (Cc), Thymus vulgraris (Tv), and Origanum heracleoticum (Oh) exhibited maximum inhibition of B. cinerea mycelial growth. The three essential oils altered the hyphal morphology and ultrastructure and resulted in many blebs around the hyphae. The essential oils damaged the plasma membrane of B. cinerea cells and resulted in the leakage of intercellular nucleic acids, proteins and soluble sugars. The exposure of strawberries to the vapors of these three essential oils in commercial package reduced gray mold, with Tv and Oh exhibiting strong efficiency and disease index reduction by 53.85% and 57.69%, respectively. Oh also inhibited postharvest decay and maintained fruit quality, preventing weight loss and soluble solid degradation. The study proposes using plant essential oils as an alternative to chemical fungicides in controlling the gray mold of strawberries.